The overall goal of this proposal project is to determine the nucleotide sequence of biologically interesting regions on human adenovirus genomes in order to understand their possible role in DNA replication transcription or as recognition sequence for packaging the DNA into mature virus particles. Initially, the terminally redundant region of human adenovirus DNA molecules of 3 major serotypes, adenovirus 2,7 and 12 will be sequenced. This region is biologically important because most of the adenovirus DNA molecules so far tested has this unique property. There are some indications that there is a correlation between the length of this region and the oncogenic potential of the virus. The research project will be carried out in two stages (a) to determine a short nucleotide sequence of 12-20 nucleotides from the termini of adenovirus 2,7 and 12. (b) To determine the complete nucleotide sequence of the terminally redundant regions from each of the three major adenovirus serotypes (200-500 nucleotides).